Burden of respiratory syncytial virus disease across the lifespan in Australia and New Zealand: a scoping review.

OBJECTIVES: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infection in young children worldwide. RSV is increasingly associated with severe respiratory disease in people aged >65 years. The heterogeneous landscape of RSV in Australia and New Zealand makes generalisation of results from global studies to local contexts difficult. Given the changing landscape of RSV, we aimed to examine the existing literature on the burden of RSV disease and identify evidence gaps in Australia and New Zealand. STUDY DESIGN: Scoping review. METHODS: We designed a scoping review protocol and searched the Web of Science and Scopus databases for eligible peer-reviewed publications. Data from eligible studies were charted and summarised in tabular and narrative form. RESULTS: Of the 153 eligible publications identified, 123 investigated RSV disease in a hospital setting and six in primary care. Only six studies reported the economic burden of disease, all of which estimated direct healthcare costs associated with treatment and/or hospitalisation; no studies quantified the indirect costs or costs to families. CONCLUSIONS: In this scoping review, we describe the effect of RSV disease in several high-risk populations, including children and adults. An improved understanding of the RSV burden of disease, both in primary care settings and economically, within the local context will assist with the implementation of preventative strategies, including vaccination programmes. Future studies to determine the true burden of RSV-associated morbidity, mortality and economic burden across the entire patient journey and among different healthcare settings will help prioritise emerging RSV therapeutics.

High burden of RSV hospitalization in very young children: a data linkage study.

Linked administrative population data were used to estimate the burden of childhood respiratory syncytial virus (RSV) hospitalization in an Australian cohort aged <5 years. RSV-coded hospitalizations data were extracted for all children aged <5 years born in New South Wales (NSW), Australia between 2001 and 2010. Incidence was calculated as the total number of new episodes of RSV hospitalization divided by the child-years at risk. Mean cost per episode of RSV hospitalization was estimated using public hospital cost weights. The cohort comprised of 870 314 children. The population-based incidence/1000 child-years of RSV hospitalization for children aged <5 years was 4·9 with a rate of 25·6 in children aged <3 months. The incidence of RSV hospitalization (per 1000 child-years) was 11·0 for Indigenous children, 81·5 for children with bronchopulmonary dysplasia (BPD), 10·2 for preterm children with gestational age (GA) 32-36 weeks, 27·0 for children with GA 28-31 weeks, 39·0 for children with GA <28 weeks and 6·7 for term children with low birthweight. RSV hospitalization was associated with an average annual cost of more than AUD 9 million in NSW. RSV was associated with a substantial burden of childhood hospitalization specifically in children aged <3 months and in Indigenous children and children born preterm or with BPD.

Integrated cluster- and case-based surveillance for detecting stage III zoonotic pathogens: an example of Nipah virus surveillance in Bangladesh.

This paper explores the utility of cluster- and case-based surveillance established in government hospitals in Bangladesh to detect Nipah virus, a stage III zoonotic pathogen. Physicians listed meningo-encephalitis cases in the 10 surveillance hospitals and identified a cluster when ⩾2 cases who lived within 30 min walking distance of one another developed symptoms within 3 weeks of each other. Physicians collected blood samples from the clustered cases. As part of case-based surveillance, blood was collected from all listed meningo-encephalitis cases in three hospitals during the Nipah season (January-March). An investigation team visited clustered cases' communities to collect epidemiological information and blood from the living cases. We tested serum using Nipah-specific IgM ELISA. Up to September 2011, in 5887 listed cases, we identified 62 clusters comprising 176 encephalitis cases. We collected blood from 127 of these cases. In 10 clusters, we identified a total of 62 Nipah cases: 18 laboratory-confirmed and 34 probable. We identified person-to-person transmission of Nipah virus in four clusters. From case-based surveillance, we identified 23 (4%) Nipah cases. Faced with thousands of encephalitis cases, integrated cluster surveillance allows targeted deployment of investigative resources to detect outbreaks by stage III zoonotic pathogens in resource-limited settings.

Impact of neighborhood biomass cooking patterns on episodic high indoor particulate matter concentrations in clean fuel homes in Dhaka, Bangladesh.

Exposure to particulate matter (PM2.5 ) from the burning of biomass is associated with increased risk of respiratory disease. In Dhaka, Bangladesh, households that do not burn biomass often still experience high concentrations of PM2.5 , but the sources remain unexplained. We characterized the diurnal variation in the concentrations of PM2.5 in 257 households and compared the risk of experiencing high PM2.5 concentrations in biomass and non-biomass users. Indoor PM2.5 concentrations were estimated every minute over 24 h once a month from April 2009 through April 2010. We found that households that used gas or electricity experienced PM2.5 concentrations exceeding 1000 µg/m(3) for a mean of 35 min within a 24-h period compared with 66 min in biomass-burning households. In both households that used biomass and those that had no obvious source of particulate matter, the probability of PM2.5 exceeding 1000 µg/m(3) were highest during distinct morning, afternoon, and evening periods. In such densely populated settings, indoor pollution in clean fuel households may be determined by biomass used by neighbors, with the highest risk of exposure occurring during cooking periods. Community interventions to reduce biomass use may reduce exposure to high concentrations of PM2.5 in both biomass and non-biomass using households.

Indoor exposure to particulate matter and the incidence of acute lower respiratory infections among children: a birth cohort study in urban Bangladesh.

Approximately half of all children under two years of age in Bangladesh suffer from an acute lower respiratory infection (ALRI) each year. Exposure to indoor biomass smoke has been consistently associated with an increased risk of ALRI in young children. Our aim was to estimate the effect of indoor exposure to particulate matter (PM2.5 ) on the incidence of ALRI among children in a low-income, urban community in Bangladesh. We followed 257 children through two years of age to determine their frequency of ALRI and measured the PM2.5 concentrations in their sleeping space. Poisson regression was used to estimate the association between ALRI and the number of hours per day that PM2.5 concentrations exceeded 100 µg/m(3) , adjusting for known confounders. Each hour that PM2.5 concentrations exceeded 100 µg/m(3) was associated with a 7% increase in incidence of ALRI among children aged 0-11 months (adjusted incidence rate ratio (IRR) 1.07, 95% CI 1.01-1.14), but not in children 12-23 months old (adjusted IRR 1.00, 95% CI 0.92-1.09). Results from this study suggest that reducing indoor PM2.5 exposure could decrease the frequency of ALRI among infants, the children at highest risk of death from these infections.

Nipah virus outbreak with person-to-person transmission in a district of Bangladesh, 2007.

In February 2007 an outbreak of Nipah virus (NiV) encephalitis in Thakurgaon District of northwest Bangladesh affected seven people, three of whom died. All subsequent cases developed illness 7-14 days after close physical contact with the index case while he was ill. Cases were more likely than controls to have been in the same room (100% vs. 9.5%, OR undefined, P<0.001) and to have touched him (83% vs. 0%, OR undefined, P<0.001). Although the source of infection for the index case was not identified, 50% of Pteropus bats sampled from near the outbreak area 1 month after the outbreak had antibodies to NiV confirming the presence of the virus in the area. The outbreak was spread by person-to-person transmission. Risk of NiV infection in family caregivers highlights the need for infection control practices to limit transmission of potentially infectious body secretions.